Re: More thoughts about planner's cost estimates - Mailing list pgsql-hackers

From David Fetter
Subject Re: More thoughts about planner's cost estimates
Date
Msg-id 20060602205611.GA23684@fetter.org
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In response to Re: More thoughts about planner's cost estimates  (Michael Dean <mdean@sourceview.com>)
List pgsql-hackers
On Fri, Jun 02, 2006 at 01:39:32PM -0700, Michael Dean wrote:

> I'm sorry to interrupt your esoteric (to me) discussion, but I have
> a very simple question:  would you define a "good unbiased sample"?
> My statistics professor Dan Price (rest his soul) would tell me
> there are only random samples of some sort, and "other", which are
> always biased, and never good.

What's at issue here is a biased estimator, not a biased sample.  If
you know an unbiased estimator of multiplicity based on a random
sample, that would be a great :)

Cheers,
D
-- 
David Fetter <david@fetter.org> http://fetter.org/
phone: +1 415 235 3778        AIM: dfetter666                             Skype: davidfetter

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